Effect Of Tissue Regulation On Dissolution Behavior Of Aluminum Based Sacrificial Anode In Deep Sea

Aluminum based sacrificial anode alloys are usually used in industrial production as cast.However,due to the defects of grain structure of as cast alloys,there are some problems such as uneven dissolution and low activity in deep sea environment.In order to solve the problems existing in the service of aluminum based sacrificial anode in deep sea environment and improve its protection effect,this paper studies the influence of grain structure on alloy dissolution behavior,and the rolling method was used to control the microstructure of sacrificial anode,and explores the influence of rolling treatment on the dissolution behavior of sacrificial anode and the optimal rolling process.In this paper,the electrochemical test,dissolution morphology observation and other performance tests were carried out from the surface to the core of the as cast aluminum base sacrificial anode alloy,including the surface fine grain area,columnar crystal area and equiaxed crystal area in the core,to study the effect of grain structure on the dissolution behavior of the alloy.The results show that the alloy with fine and uniform equiaxed crystal zone has low open circuit potential,uniform and comprehensive dissolution morphology and good discharge performance in shallow sea and deep sea environment;simultaneously,due to the uneven and coarse grain structure in the surface fine-grained area and columnar crystal area,the open circuit potential is unstable,the surface state is uneven,the self-corrosion rate is large and local corrosion is serious and the protection effect is poor.In order to obtain fine and uniform equiaxed grains,the cast alloy was hot rolled by different rolling processes,and the properties of several rolled alloys were tested by electrochemical test and morphology observation.The results show that the potential of the alloy with 92.5% deformation rate and 97% deformation rate is low and stable in deep sea environment,the self corrosion rate is small,and the surface dissolution is uniform.The comparison results show that the surface activity and discharge properties of the rolled alloy are improved,and the self corrosion rate is reduced.